二叉树算法，
顺序确定的， 小的放在左边，大的放在右边。
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace BineryTree { class Program { static void Main(string[] args) { Tree<int> tree = new Tree<int>(55); tree.Insert(33); tree.Insert(34); tree.Insert(32); tree.Insert(45); tree.Insert(67); tree.Insert(65); tree.Insert(56); tree.Insert(66); tree.Insert(68); tree.Insert(69); tree.MiddleOrder(tree); Console.WriteLine(); Console.WriteLine("Max:" + tree.FindMax()); Console.WriteLine("Min:" + tree.FindMin()); var tree1 = tree.FindTree(67); if (tree1 != null) { tree1.MiddleOrder(tree1); } Console.WriteLine(); var root = tree.Delete(34); tree.MiddleOrder(root); Console.Read(); } } public class Tree<T> where T : IComparable<T> { /// <summary> /// Current node /// </summary> public T NodeData { get; set; } /// <summary> /// Left Node /// </summary> public Tree<T> LeftNode { get; set; } /// <summary> /// Right Node /// </summary> public Tree<T> RightNode { get; set; } public Tree(T node) { NodeData = node; } public void Insert(T node) { T currentNode = NodeData; if (currentNode.CompareTo(node) > 0) { if (LeftNode == null) { LeftNode = new Tree<T>(node); } else { LeftNode.Insert(node); } } else { if (RightNode == null) { RightNode = new Tree<T>(node); } else { RightNode.Insert(node); } } } /// <summary> /// 前序遍历，也叫先根遍历，遍历的顺序是，根，左子树，右子树 /// </summary> /// <param name="root"></param> public void PreOrder(Tree<T> root) { if (root != null) { Console.Write(root.NodeData + " "); PreOrder(root.LeftNode); PreOrder(root.RightNode); } } /// <summary> /// 中序遍历，也叫中根遍历，顺序是 左子树，根，右子树 /// </summary> /// <param name="root"></param> public void MiddleOrder(Tree<T> root) { if (root != null) { MiddleOrder(root.LeftNode); Console.Write(root.NodeData + " "); MiddleOrder(root.RightNode); } } /// <summary> /// 后序遍历，也叫后根遍历，遍历顺序，左子树，右子树，根 /// </summary> /// <param name="root"></param> public void PostOrder(Tree<T> root) { if (root != null) { PostOrder(root.LeftNode); PostOrder(root.RightNode); Console.Write(root.NodeData + " "); } } /// <summary> /// 查找最大指 /// </summary> /// <returns></returns> public T FindMax() { Tree<T> currentRoot = this; while (currentRoot.RightNode != null) { currentRoot = currentRoot.RightNode; } return currentRoot.NodeData; } /// <summary> /// 查找最小值 /// </summary> /// <returns></returns> public T FindMin() { Tree<T> currentRoot = this; while (currentRoot.LeftNode != null) { currentRoot = currentRoot.LeftNode; } return currentRoot.NodeData; } public Tree<T> FindTree(T data) { Tree<T> currentRoot = this; while (true) { if (currentRoot.NodeData.CompareTo(data) > 0) { if (currentRoot.LeftNode == null) break; currentRoot = currentRoot.LeftNode; } else if (currentRoot.NodeData.CompareTo(data) < 0) { if (currentRoot.RightNode == null) break; currentRoot = currentRoot.RightNode; } else { return currentRoot; } } if (currentRoot.NodeData.CompareTo(data) != 0) { return null; } return currentRoot; } public Tree<T> Delete(T data) { var rootNode = this; Tree<T> parent = this; Tree<T> current = this; while (true) { if (current.NodeData.CompareTo(data) > 0) { if (current.LeftNode == null) break; parent = current; current = current.LeftNode; } else if (current.NodeData.CompareTo(data) < 0) { if (current.RightNode == null) break; parent = current; current = current.RightNode; } else { // parent = null; break; } } //情况一:叶节点，直接删除 if (current.LeftNode == null && current.RightNode == null) { //如果被删节点是根节点，且没有左右孩子 if (current == rootNode && rootNode.LeftNode == null && rootNode.RightNode == null) { rootNode = null; } else if (current.NodeData.CompareTo(parent.NodeData) < 0) parent.LeftNode = null; else parent.RightNode = null; } //情况二，所删节点只有左孩子节点时 else if (current.LeftNode != null && current.RightNode == null) { if (current.NodeData.CompareTo(parent.NodeData) < 0) parent.LeftNode = current.LeftNode; else parent.RightNode = current.RightNode; } //情况三，所删节点只有右孩子节点时 else if (current.LeftNode == null && current.RightNode != null) { if (current.NodeData.CompareTo(parent.NodeData) < 0) parent.LeftNode = current.RightNode; else parent.RightNode = current.RightNode; } //情况四，所删节点有左右两个孩子 else { //current是被删的节点，temp是被删左子树最右边的节点 Tree<T> temp; //先判断是父节点的左孩子还是右孩子 if (current.NodeData.CompareTo(parent.NodeData) < 0) { parent.LeftNode = current.LeftNode; temp = current.LeftNode; //寻找被删除节点最深的右孩子 while (temp.RightNode != null) { temp = temp.RightNode; } temp.RightNode = current.RightNode; } //右孩子 else if (current.NodeData.CompareTo(parent.NodeData) > 0) { parent.RightNode = current.LeftNode; temp = current.LeftNode; //寻找被删除节点最深的左孩子 while (temp.RightNode != null) { temp = temp.RightNode; } temp.RightNode = current.RightNode; } //当被删节点是根节点，并且有两个孩子时 else { temp = current.LeftNode; while (temp.RightNode != null) { temp = temp.RightNode; } temp.RightNode = rootNode.RightNode; rootNode = current.LeftNode; } } return rootNode; } } }
